I saw lots of stray dogs when we were in Moscow a couple of years ago. I never saw any on the Metro.

…there are some 500 strays that live in the metro stations, especially during the colder months, but only about 20 have learned how to ride the trains. This happened gradually, first as a way to broaden their territory. Later, it became a way of life. “Why should they go by foot if they can move around by public transport?” he asks.

“They orient themselves in a number of ways,” Neuronov adds. “They figure out where they are by smell, by recognising the name of the station from the recorded announcer’s voice and by time intervals. If, for example, you come every Monday and feed a dog, that dog will know when it’s Monday and the hour to expect you, based on their sense of time intervals from their biological clocks.”

Tip: For an inexpensive deodorizer, put some orange peel in the oven at 350F with the door ajar. If you have a really powerful odor to deal with, boil some cloves in a mixture of 1 cup of water and 1/4 cups of vinegar.